Louise Male

An electrosynthetic oxidation protocol converts phenothiazine antipsychotics into clinically relevant sulfoxide metabolites and reveals unprecedented piperazine ring-opening pathways, offering a green route to drug-metabolite standards.

Multivariate compositions of zinc halide dipyridyl-naphthalenediimide coordination polymers are shown to directly tune photochromic response.

Foldamers have been widely used as responsive motifs within discrete supramolecular systems on account of their programmable stimuli-sensitivity. However, translation of this functionality into bulk matter and toward the creation of smart materials, such as switchable metallogels, remains largely unexplored. Further, characterization of local structure in metallogel networks is inherently challenging because of their semisolid nature, precluding the use of solution phase NMR spectroscopy. We report a dual light- and pH-responsive foldamer metallogel, comprised of aromatic oligoamide foldamers coordinated to palladium(II) centers. We show reversible gel–sol–gel behavior using UV illumination and subsequent heat treatment. Exposure to aqueous acid also induces a gel–sol transition. We determine the local structure of the gel using magic angle spinning (MAS) dynamic nuclear polarization (DNP) NMR spectroscopy. We thus identify square planar 4-fold coordination of Pd (II) by terminal pyridines in the foldamer as the primary structural motif comprising the gel backbone. Finally, successful exchange of the organic solvent with water, without compromising the gel structure, leads to the first example of a metallo-foldamer hydrogel.

Positional isomerism in pyridyl naphthalene diimide formic acid co-crystals controls reversible photochromic switching behaviour upon UV irradiation via a proton-coupled electron transfer type mechanism.

α‐Silyl alkyl complexes, such as the ubiquitous MCH ₂ SiMe ₃ , are some of the most used organometallic building blocks and reagents. Hitherto, most reports focus on the reactive metal–carbon bond, while the carbon–silicon bond has thus far been limited to a handful of serendipitous reaction patterns. Herein, by examining a range of reactions between mononuclear Li or Na α‐silyl alkyl complexes and CO, CO ₂ , or heteroallenes (isocyanates, isothiocyanates, carbodiimides), we report tandem M─C and C─Si bond reactivity, with in‐depth mechanistic understanding unveiled by computational reaction pathway studies enabled by the artificial force induced reaction (AFIR) method. By bringing the long‐neglected C─Si bond reactivity to the awareness of synthetic chemists, we demonstrate that the C─Si bond should be taken into account in reaction design when using these α‐silyl alkyl complexes.

α‐Silyl alkyl complexes, such as the ubiquitous MCH ₂ SiMe ₃ , are some of the most used organometallic building blocks and reagents. Hitherto, most reports focus on the reactive metal–carbon bond, while the carbon–silicon bond has thus far been limited to a handful of serendipitous reaction patterns. Herein, by examining a range of reactions between mononuclear Li or Na α‐silyl alkyl complexes and CO, CO ₂ , or heteroallenes (isocyanates, isothiocyanates, carbodiimides), we report tandem M─C and C─Si bond reactivity, with in‐depth mechanistic understanding unveiled by computational reaction pathway studies enabled by the artificial force induced reaction (AFIR) method. By bringing the long‐neglected C─Si bond reactivity to the awareness of synthetic chemists, we demonstrate that the C─Si bond should be taken into account in reaction design when using these α‐silyl alkyl complexes.

The sodium anion (sodide) is an uncommon alkali metal species, whose reactivity has been scarcely studied, with previous reports limited to decomposition and quenching reactions of ill-characterized species formed in situ. Based on our recent report of the first gram-scale synthesis of a well-characterized sodide complex, [Na⁺(2,2,2-cryptand)]Na^- (1), we now describe its reactivity with phenyl-substituted ethylenes and a cyclic polyolefin. Depending on the substitution pattern, 1 mediates either 1-electron or 2-electron reduction. Reaction with a cyclic multiolefin, 1,3,5,7-cyclooctatetraene (COT), exhibits two-electron reduction to produce COT^2- species.

The isomer selective formation of heteroleptic Pd₂L^A₂L^B₂-type coordination cages assembled from low-symmetry ligands was demonstrated through tuning of coordination sphere interactions.

The targeted formation of low-symmetry coordination cages represents a significant design challenge, but offers the potential to engineer bespoke molecular hosts with precision. In this work, we have combined the design principles of geometric complementarity and coordination sphere engineering to direct the site- and orientation-selective self-assembly of heteroleptic Pd2LA2LB2-type coordination cages from low-symmetry ligands. The effects of different combinations of heterocyclic donors and their locations within the cage structures on isomer distributions were studied, providing insights on shifts in the balance between non-covalent interactions in the first and second coordination spheres of the cages. For cages with one low-symmetry ligand, switching between selective formation of syn- (up to 77%) or anti-isomers (up to 76%) was achieved simply through minor structural changes (swapping a hydrogen atom for a fluorine) or changing the location of heterocycles within the cage structure between the different ligand scaffolds. Furthermore, the selective (up to ~62%) assembly of particular isomers of heteroleptic cages formed from two low-symmetry ligand scaffolds was demonstrated and rationalised.

The photodegradation of ketones, including polyketones, by Norrish degradation pathways is well established. However, these mechanistic pathways lead to uncontrolled reactions, which in the case of plastics, result in in-complete degradation and the formation of microplastic fragments. Using an organocatalyzed thiol-yne step-growth polymerization, we developed poly(enone sulfides) that display useful properties and undergo a highly selective photodegradation into non-cytotoxic diketone and disulfide products. Model substrate reactions, sup-ported by computational modelling, revealed the molecular features that enable the selective degradative path-way to occur, implicating both radical and reactive oxygen species. The synthetic approaches for monomers and polymers are versatile and allow for the design of a range of polymer structures with divergent thermomechanical properties, with some photodegradable materials being tough thermoplastics possessing high strength and ductil-ity.